Polycyano lubricating oil detergents



Unite States Patent @fiFice 3,376,220 Patented Apr. 2, 1968 ABSTRACT OF THE DISCLOSURE Lubricating oil compositions containing oil soluble aralkyl polycyano compounds having an oil solubilizing aliphatic hydrocarbon amino substituent, thecompounds providing detergency and dispersancy.

This invention concerns lubricating oil compositions containing polycyano amines as lubricating oil detergents.

A development of major importance in the lubricating oil field has been, theintroduction of ashless, detergents, that is, metal free compounds which are capable of reducing varnish and sludge deposits in internal combustion engines. An important advantage of these ashless detergents is .the avoidance of the ash formed by the metal salt detergents on decomposition. Thus, valve andcombustion chamber deposition with accompanying octane requirement increase can be minimized through their use.

This invention concerns aminoaryl substituted polycyano aliphatic hydrocarbons having, 2 nitrogen substituents of a total of at least 30 carbon atoms. The aliphatic hydrocarbon group has from 1 to .3 carbon atoms and from 2 to 4 cyano groups.

For the most part, the lubricating, oil detergent employed in the compositions of this invention will have the following formula:

wherein R and R are aliphatic hydrocarbon radicals having a total of at least 30 carbon atoms, Ar is an aryl group, generally carbocyclic, of from 6 to 10 carbon atoms, X is an aliphatic hydrocarbon group of from 1 to 3 carbon atoms, and n is an integer of from 2 to 4, usually 3. Generally, at least one of R and R will be at least '16 carbon atoms. More usually, one of R R will be at least carbon atoms and the other-will be lower alkyl, i.e., alkyl of from 1 to 6 carbon atoms.

Usually, the composition will have a total of from about to 500 carbon atoms, more usually from about to 300 carbon atoms. Ar will usually be either phenyl or naphthyl, more usually phenyl. R and R may be hexadecyl, octadecyl, eicosyl, polyisobutenyl, polypropenyl, etc. When one of R and R is lower alkyl, it may be methyl, ethyl, isopropyl, hexyl, etc. R and R may be either saturated or unsaturated, but will usually be unsaturated. The X may represent methyl, ethyl, propyl or vinyl, with at least two of the hydrogens replaced by cyano groups.

For the most will have thefollowing formula:

and

part, the compositions of this invention wherein R about 30 to group.

Illustrative R groups are polyisobutenyl, polypropenyl, etc. These long chain hydrocarbons may be readily achieved by the polymerization of low molecular weight monomers, e.g., propylene, ethylene, isobutylene, etc.

The compositionswithin the scope of'this invention are prepared differently, depending on the particular compound. With the tricyanovinyl derivative, tetracyanoethylene may be contacted with the particular tertiary amine at an elevated'temperature. With the other polycyano compounds, the analogous halo compound may becontacted with the aryl amine in the presence of a protonic acid catalyst, e.g., HP, or other means known in the art. The lubricating fluids (hereinafter referred to as oils) which are combined with the detergent compounds can be derived from natural or synthetic sources. Oils generallyhave viscosities of bolt Universal seconds (SUS) at 100 F. Among natural hydrocarbonaceous oils are paraffin base, naphthenic base, asphaltic base and mixed base oils. Illustrative of the synthetic oils are: hydrocarbon oils, such as polymers of various olefins; and alkylated aromatic hydrocarbons; and non-hydrocarbon oils, such as polyalkylene oxides,

aromatic ethers, carboxylate esters, phosphate esters and" silicon esters. The preferred media are the hydrocarbonaceous media, both natural and-synthetic.

The ,above oils may be used individually or together,- whenever miscible or made so by the use of mutual solvents.

The detergent will generally be compounded with the lubricating oil in amounts of at least about one weight percent and usually not more than 20 Weight percent, more usually in the range of about 1.5 to 15 weight percent, when being used in an internal combustion engine.

The detergents, however, can be prepared as concentrates due to their excellent compatibility with oils. As cone centrates, the compounds of this inventionwill generally range from about 20 to weight percent of thetotalcomposition.

Usually included in the oils are other additives, such as extreme pressure agents, rust inhibitors, antioxidants,

oiliness agents, foam inhibitors, viscosity index improvers, pour point depressants and occasionally other detergents. Usually, these will be present in the range from about 0.01 to 10 weight percent, more usually from about 0.5 to 5 weight percent of the composition, generally,

each of the additives will be present inthe range from about 0.01 to A preferred lubricating oil.

5 weight percent of the composition.

compositions of this invention is toinclude in the oil from about 1 to 50mM./kg. of an 0,07.

dihydrocarbyl phosphorodithioate, wherein-the hydro:

carbyl groups are from about 4 to 30 carbon atoms. The,

remaining valence may be satisfied by zinc, a polyalkyleneoxy or athirdhydrocarbyl group.

The following examples are oifered by wayof illustration and not by way of limitation.

EXAMPLE A Into a reaction flask was introduced 967 g. (approximately 1 mole) of 82.7 percent active (the diluent was mixed hexanes) of polyisobutenyl monobromide (the polyisobutene group is an aliphatic hydrocarbon group of from- 200 carbon atoms, and R is a lower alkyl' from about 35 to 50,000 Say-' aspect in using the detergent containing had a molecular weight of aboutv 900) and 536 g. (5 moles) of N-methylaniline and the mixture heated with stirring to 150 C. The temperature was maintained for about 6 hours. The mixture was then allowed to cool, extracted with a 50/50 water/ethanol mixture, dried and solvent removed in vacuo. The residue was dissolved in mixed hexanes and extracted again with a 50/50 water/ethanol mixture until the extracts were water white. After drying the organic phase with sodium sulfate, the volatile solvents were removed in vacuo. To insure the complete removal of aniline, the residue was heated to 150 C. at mm. Hg while nitrogen was bubbled through the mixture. The residue weighed 767 g.

AnaZysis.-Percent N, 0.97, 0.92; mol. wt., 1076 (ThermoNAM-Differential Vapor Pressure Technique).

EXAMPLE I Into a reaction flask was introduced and heated to 70 C., 420 g. (0.29 mole) of the product prepared in Example A. To the hot N-substituted aniline was added 33.5 g. (0.262 mole) of tetracyanoethylene. The temperature was increased to 100 C. and maintained for 4 hours. At the end of this time, the mixture was cooled, diluted with mixed hexanes and filtered. After stripping oif the volatile solvents, the residue weighed 475 g.

Analysis.Percent total N, 4.37, 4.37; percent basic N, 0.17, 0.18.

EXAMPLE B Into a reaction flask was introduced 2,070 g. (1.5 moles) of polyisobutylene monobromide and 578 g. (6

moles) of aniline, the aniline being added slowly to maintain the temperature at about room temperature. When the addition of aniline was completed, the mixture was diluted with 500 ml. of benzene and enough hexane to make the solution hazy (about 1.5 liters). The mixture was then heated to reflux and the temperature maintained for 8 hours. After allowing the mixture to cool, the mixture was filtered, then washed with 6 normal aqueous hydrochloric acid followed by washing with concentrated sodium hydroxide solution. The organic phase was then repeatedly washed with a 1:1 ethanol/Water mixture until neutral to'faH paper. After drying the organic phase, the volatile materials were removed in vacuo, leaving a residue of 1,586 g.

Analysis.-Percent N, 0.64, 0.65.

EXAMPLE II Into a reaction vessel was introduced 1,085 g. (0.5 mole) of the product prepared in Example B, heated to 70 C. and 59.4 g. (0.45 mole) of tetracyanoethylene added over a period of about 1 hour. The temperature was then raised to 100-110 C. and the mixture stirred with nitrogen bubbling under the surface for 6-8 hours. At the end of this time, the reaction mixture was allowed to cool and the product isolated.

In order to demonstrate the effectiveness of the cornpositions of this invention, the compositions of Examples I (prior to ether extraction) and II were tested in a modified FL-2 test procedure, as described in the June 21, 1948, report of the Coordinating Research Council. This test simulates automobile engine performance. A standard procedure requires the maintenance of a jacket temperature of 95 F. and a crankcase oil temperature of 155 F. at 2,500 rpm. and brake horsepower for 40 hours (closely simulating the relatively cold engine conditions which are normally experienced in city driving). At the end of each test, the engine is dismantled and the amount of total sludge (rating of 0 to 50, no sludge being and clogging of the rings and oil screen (rating of 0 to 100, no clogging being 0) is determined. The above test was modified by increasing the time and periodically raising the oil sump temperature from 165 F. to 205 F. and the water jacket temperature from 95 F. to 170 F.

Using a Mid-Continent SAE 30 base stock, the exemplary detergent of Example I was employed at 4 weight percent concentration, while the exemplary detergent of Example II was employed at 0.85 weight percent; with the detergent of Example I, also included in the oil was 10 mM./kg. of zinc 0,0-di(alkyl dithiophosphate) (alkyl of from 4 to 6 carbon atoms) and 2 mM./kg. of zinc 0,0-di(alkylphenyl)dithiophosphate (alkyl is polypropylene of from 12 to 15 carbon atoms), while with the detergent of Example II, half the amounts were used. Using the detergent prepared in Example I, at the end of hours, total sludge was rated at 36.2, clogging at 59 and percent oil screen clogging at 9.8. For the detergent of Example II, after 60 hours, total sludge was rated at 31.9, percent oil ring clogging at 70 and percent oil screen clogging at 40. With base oil, the engine is usually incapable of any further operation after about 12 hours.

To further demonstrate the effectiveness of the detergent containing lubricating oil compositions of this invention, the exemplary composition prepared in Example 1 was tested under Caterpillar 1-G conditions (MIL-L- 45199). To a Mid-Continent SAE'30 base oil was added 1.685 weight percent of the detergent and 12 mM./kg. of zinc 0,0-di(alkylphenyl) phosphorodithioate (the alkyl is polypropylene of an average of 14 carbon atoms). The test was carried out for 60 hours. For the groove deposits measured on a rating of 0 to 100, 100 being completely filled, the results were 45-8-0-0. For the land deposits, rated from 0 to 800, 800 being completely black, the results were 320-25-30. For comparison, base oil containing the phosphorodithioate has groove deposits rated as 93-15-5-3 and land deposits at 500-800-370.

It is evident from the above results that the lubricating oil compositions of this invention provide excellent detergency and lubrication in internal combustion engines, not only under the hot conditions of the diesel engine, but

under the more varying and cooler conditions of the automobile engine. The presence of the cyano group also aids in providing some corrosion inhibition, lead copper bearings.

As will be evident to those skilled in the art, various modifications on this invention can be made or followed, in the light of the foregoing disclosure and discussion, without departing from the spirit or scope of the disclosure or from the scope of the following claims.

We claim:

1. A lubricating oil composition comprising an oil of lubricating viscosity and in an amount suificient to provide detergency and dispersancy, a compound of the formula:

particularly with wherein R and R are aliphatic hydrocarbon radicals having a total of at least 30 carbon atoms, Ar is an aryl group of from 6 to 10 carbon atoms, X is an aliphatic hydrocarbon group of from 1 to 3 carbon atoms and n is an integer of from 2 to 4.

2. A lubricating oil composition comprising an oil of lubricating viscosity, and in an amount sufiicient to provide detergency and dispersancy, a compound of the formula:

wherein R is an aliphatic hydrocarbon group of from about 30 to-200 carbon atoms and R is lower alkyl.

3. A lubricating oil composition according to claim 2, wherein R is polyisobutenyl.

4. A lubricating oil composition according to claim 1, having from 1 to 50 mM./kg. of an 0,0-dihydrocarbyl phosphorodithioate, wherein the hydrocarbyl groups are of from 4 to 30 carbon atoms.

percent oil ring.

wherein R and R are aliphatic hydrocarbon radicals having a total of at least 30 carbon atoms, Ar is an aryl group of from 6 to 10 carbon atoms, X is an aliphatic hydrocarbon group of from an integer of from 2 to 4.

1 to 3 carbon atoms and n is 10 References Cited UNITED STATES PATENTS Loane et a1 252-50 X Middleton 25250 X Foehr et a1. 25232.7 Dexter et a1. 252-50 X Roland 260465 DANIEL E. WYMAN, Primary Examiner. PATRICK P. GARVIN, Examiner. 

